Lubricating oil



Patented Mar. 14, 193%? UNETED YATES ang es rarer Fi;

. E. L du Pont de Nemours &

Company, Wil

mington, Del., a corporation of Delaware 'No Drawing. Application May 6, 1937, Serial No. 141,095

2.4 Claims.

This invention relates to lubricating oils and to processes for improving their properties, and more particularly to the production of lubricating oils having a reduced pour point and improved low temperature characteristics.

Lubricating oil stocks derived from paraffin and mixed base crudes contain appreciable amounts of wax, and, therefore, have a relatively high pour test unless asubstantial amount of this wax is removed. The wax may be removed by cold settling, filtration, or centrifuging. However, lubricating oil stocks, after subjection to such processes may still retain appreciable amounts of wax, and may have pour tests above 15 F. and even up to about 40 F. The removal of additional quantities of wax from these stocks necessitates expensive further processing. Furthermore, complete removal of wax from an oil frequently causes an undesirable increase in the rate of change of the viscosity of the oil with temperature, that is, such removal of wax results. in

a lower viscosity index of the oil. It is therefore of advantage to add to the oila material which will result in a product 'of lowpour point without it being necessary to remove all of the wax.

Many materials have been proposed for addition to lubricating oils for this purpose. Some'of these are condensation products of aryl hydrocarhens and chlorinated parafiin wax, fatty acids and their salts or esters.

An object or" the present invention is to pro-' vide lubricating oils of reduced pour test and improvedfiowing characteristics at low temperatures. Another object is to provide new pourcating oils. A further objectisto provide pourpoint depressants which do not have the objectionable features of the compounds-heretofore known for this purpose. A still further object is 40 to provide a method for improving the properties of lubricating oils and particularly their oiliness. Other objects are to provide new compositions of matter and to advance the art. Still other objects will appear hereinafter.

The above and other objects may be accomplished in accordance with my invention which comprises the addition to. a petroleum oil of a hydrogenated castor oil derivative. By hydrogenated castor oil derivative as used herein is meant the product obtained by causing hydro--' genated castor oil to react either with its own free hydroxyl group or with another neutral compound containing at least 6 carbon atoms selected from the classes of alcohols, aldehydes, lsocyanates, and isothiocyanates at temperatures point depressing materials to be added to lubrir.

between about F. and about 550 F. and in the presence or absence of a catalyst to impart pour-point depressing properties to it. The reac tion is caused to proceed until the hydrogenated castor oil has been so modified that it softens 5 ,between about 70 F. and 160 F., and preferably between about 90 F. and about F. The time of heat treatment of the hydrogenated castor oil either in the presence or absence of a catalyst may be varied over wide limits but may generally 10 be expected to be from about two to about eight hours in, the-presence of a catalyst and from about 16 to about 64 hours in the absence of a catalyst. Also, as is usual, the time of heat treatment will vary with the temperature employed, the higher 16 the temperature employed the lesser the time required for the reaction to take place. However, at high temperatures, there is a tendency to oxidation and decomposition and hence it is preferred to employ a temperature not substano tially in excess of 400 F.

Also the most eflicient temperature will vary with the modifying agents, e. g., when the hydrogenated castor oil is reacted with itself or with another material containing an alcoholic hy- 25 droxyl group, it is generally necessary to employ temperatures of from about 330 to about 550 F., and preferably temperatures of about 390 to about 410 F. When other modifying agents are employed, lower temperatures will ordinarily be 30 used. In any event, the temperature and time of treatment must be chosen so as to produce a soft wax for the most effective pour-point depressant. Hard waxes and liquid products are ineffective or substantially. so. -Waxes which 5 soften between about 70 F. and F. are effective.

Within the scope of the term alcohols as employed herein and in the claims, it will be understood that I intend to include hydrogenated 40 castor oil also since it still contains the secondary hydroxyl group originally present in the castor oil. In fact, the products obtained by the simple heat treatment of the hydrogenated castor oil in the presence or absence of a catalyst con- 45 stitutes the preferred embodiment of my invention.

,The catalyst to be employed should be one selected from the alkali metals,- alkali metal a1 koxides, alkaline earth metal oxides, lead oxide, 50 tin oxide, aluminum oxide, chromium oxide and nickel oxide. Of these/ the preferred catalysts are lead oxide and tin dxide.

The concentration of pour-point depressing material to be employed in the oil will be deter- 55 mined by the pour point desired in the finished product and by the amount of paraffin waxoriginally present in the oil. Generally, quantities varying from 0.3% to 0.6% will be effective in producing a pour point of 0 F. or less. However, one may employ as little as 0.1% or as much as 2% or more, if necessary.

In order to more clearly illustrate my invention, the preferred modes of carrying same into effect and the advantageous results to be obtained thereby, the "following examples are given. In the preparation of the various derivatives described in these examples, a hydrogenated castor oil was employed which conformed to the following approximate characteristics: melting point, 171 F. to 178 F.; acid number, 2.0 mg. potassium hydroxide per gram of oil; saponiflcation number, 180 mg. potassiumhydroxide per gram of oil; iodine absorption, 30 mg. iodine per gram of 011. Such hydrogenated castor oil, per se, had no effect in depressing the pour point of a partially dewaxed paraifin base oil having an original pour point of 25 F. In each example, solution of the hydrogenated castor oil derivative in the mineral oil was effected by moderate warming and stirring. Pour points were determined according to ASTM method D-97-34.

Example 1 The hydrogenated castor oil was heated to 392 F. for 2 hours with 1 per cent lead oxide. The product was a soft wax having the following characteristics: softening point, 131 F.-149 F.; iodine absorption, 45 mgs. iodine per gram of oil; acid number, 6.2 mg. potassium hydroxide per gram of oil; hydroxyl number, 160 mg. potassium hydroxide per gram of oil. This material, added to the previously mentioned oil of 25 F. pour point, gave the following results:

Percent b weight 0 pour-point depressant Pouggoint,

Example 2 The hydrogenated castor oil was heated at 392 F. for 16 hours without a catalyst. The resulting product was a wax similar to that obtained in Example 1, but softening at 160 to 163 F. One per cent of this material by weight, added to the 25 F. lubricating oil, depressed the pour point to Example 4 'Iiurty-three grams'of hydrogenated castor oil were dissolved in 100 cc. benzene and 19.9 grams ofdodecylisocyanate were added. The resulting pene' alcohols, fenchyl branched chain alcohols derived from oxidation solution was refluxed 10 hours. After removal of the solvent, a. cream-colored wax was secured which softened at 113 F. to 131 F. One per cent of this material, dissolved in the test oil, lowered the pour point to 15 F.

Example 5 Ten grams of hydrogenated castor oil were dissolved in 100 cc. benzene and '7' grams of decamethylene diisocyanate were added. The solution was refluxed for 5 hours and the solvent then removed by evaporation. The resulting product was a light yellow wax which softened at 143 to 150 F., 1 per cent of which lowered the pour point of the test oil to -10 F.

Example 6- Example 7 Ten grams of hydrogenated castor oil were dissolved in cc. benzene and 5 grams of 2-ethyl hexenal were added along with a few drops of hydrochloric acid. The mixture was allowed to stand at F. to F; for three days. On evaporation of the solvent, a brown wax was secured which softened at 138 to F. and which, in 1 per cent concentration, lowered the pour point of the test oil to 0 F.

The above examples are illustrative only. Many other alcohols, aldehydes, isocyanates, and isothiocyanates will be readily apparent to those skilled in the art. The isocyanates and isothiocyanates containing aliphatic, cycloaliphatic, or aryl groups are suitable. The compounds to be reacted with the castor oil neednot be pure materials but may be mixtures. For example, I may use alcohols derived from the hydrogenation of carbon oxides or aldehydes secured by the oxidation of these alcohols; naphthenyl alcohols, teralcohol, straight or of petroleum and alcohols derived by the hydrogenation of animal and vegetable oils.

In the above examples, the derivatives, were prepared from a certain hydrogenated castor oil. Castor oil hydrogenated to a different extent may be employed but it is generally preferable to employ a hydrogenated castor oil having a softening point of at least F. and particularly castor oil which has been substantially completely hydrogenated.

In the examples given above, the modifying treatment has'been applied to castor oil after hydrogenation. In the case of the simple heat treatment either in the absence or in the presence of a catalyst and in the case of the other reaction materials, products of substantially the same general characteristics may be secured by reacting the castor oil itself with the modifying agents and then hydrogenating the resulting products. Aiternatively, similar products could be secured by dissolving the materials in the mineral oil and causing them to react by the application of cats.- lysts and heat.

It will thus be apparent that I have provided very effective pour-point depressants by modifying hydrogenated castor oil by means of modifying agents which are non-acidic in character.

5. A lubricant comprising a petroleum lubricat- The resulting products are non-acidic in character and do not readily give rise to acidic materials. Accordingly, my pour-point depressants do not increase the corrosiveness of the oils.

In addition, the hydrogenated castor oil derivatives impart increased properties of oiliness to petroleum oils generally, including those which contain no waxes. This is illustrated in the following table, which shows the coefiicients of static friction obtained by determining the force required to start a triangular steel plate set on three fixed ball bearings moving over another horizontal steel surface to which the respective lubricant had been applied.

In view of the above description wherein the preferred embodiments of my invention and the preferred modes of carrying the same into efiect have been disclosed, it will be readily apparent to those skilled in the art that many variations and modifications may be made therein without departing from the spirit of my invention. Accordingly, the scope of my invention is to be limited solely by the appended claims construed as broadly as is permissible in view of the prior art.

I claim:

1. A lubricant comprising a petroleum lubricating oil having incorporated therein a small amount of a hydrogenated castor-oil derivative having a softening point between about 70 F. and about 160 F., said hydrogenated castor oil derivative being the product of the reaction of hydrogenated castor oil with a neutral compound containing at least 6 carbon atoms selected from the class consisting of alcohols, aldehydes, isocyanates and isothiocyanates.

2. A lubricant comprising a petroleum lubricating oil having incorporated therein a small amount of a hydrogenated castor oil derivative having a softening point between about 70 F. and about 160 F., said hydrogenated castor oil derivative being the product of the reaction of hydrogenated castor oil with a neutral alcohol containing at least 6 carbon atoms.

3. A lubricant comprising a petroleum lubricating oil having incorporated therein a small amount of a hydrogenated castor oil derivative having a softening point between about 70- F. and about 160 F., said hydrogenated castor oil derivative being the product obtained by heating the hydrogenated castor oil at temperatures of about 330 F. to about 550 F.

4. A lubricant comprising a petroleum lubricating oil having incorporated therein a small amount of a hydrogenated castor oil derivative having a softening point between about 70 F. and about 160 F., said hydrogenated castor oil derivative being the product obtained by heating hydrogenated castor oil to between about 330 F. and" about 550 F. in the presence of an alkaline catalyst.

330 F. to about 550 ing oil having incorporated therein a small amount of a hydrogenated castor oil derivative having a softening point between about 70 F. and about 160 F., said hydrogenated castor oil derivative being the product obtained by heating hydrogenated castor oil to between about 390 F. and about 410 F. in the presence of an alkaline catalyst. I

6. A lubricant comprising a petroleum lubricating oil having incorporated therein a small amount of a hydrogenated castor oil derivative having a softening point between about 70 F. and about 160 F., said hydrogenated castor oil derivative being the product of the reaction of hydrogenated castor oil with a neutral isocyanate containing at least 6 carbon atoms.

7. A lubricant comprising a petroleum lubricating oil having incorporated therein a small amount of a hydrogenated castor oil derivative having a softening point between about 70 F. and about 160 F., said hydrogenated castor oil derivative being the product of the reaction of hydrogenated castor oil with dodecyl isocyanate.

8. A lubricant comprising a petroleum lubricating oil having incorporated therein a small amount of a hydrogenated castor oil derivative having a softening point between about 70 Fl earth oxides, lead oxide, tin oxide, aluminum oxide, chromium oxide and nickel oxide.

9. A lubricant comprising a petroleum lubricating oil having incorporated therein a small amount of a hydrogenated castor oil derivative having a softening point between about 70 F. and about 160 F., said hydrogenated castor oil derivative being obtained by heating the hydrogenated castor oil at temperatures of about F. in the presence of a catalyst selected from the group consisting of alkali metals, alkali metal alkoxides, alkaline earth oxides, lead oxide, tin oxide, aluminum oxide, chromium oxide and nickel oxide.

10. A lubricant comprising a petroleum lubricating oil having incorporated therein a small amount of a hydrogenated castor oil derivative having a softening point between about '70? F. and about 160 F., said hydrogenated castor oil derivative being the product of the reaction of hydrogenated castor oil with a neutral compound containing at least 6 carbon atoms selected from the class consisting of alcohols, aldehydes, isocyanates and isothlocyanates in the presence of lead oxide at temperatures between 80 F. and about 550 F. for a sufficient length of time to modify the hydrogenated castor oil so that it has a softening point between about 70 F. and about F.

11. A lubricant comprising a petroleum lubricating oil having incorporated therein a small amount of a hydrogenated castor oil derivative having a. softening point between about 70 F. and about 160 F., said hydrogenated castor oil derivative being obtained by heating the hydrogenated castor oil at temperatures of about 330 F. to about 550 F. in the presence of lead oxide.

12. An improved lubricating oil of relatively low pour point comprising a petroleum fraction of relatively higher pour point having incorporated therein a small amount of a hydrogenated castor oil derivative having a softening point between about 70 F. and about 160 F., said hydrogenated castor oil derivative being the product of the reaction of hydrogenated castor oil with a neutral compound containing at least 6 carbon atoms selected from the class consisting of alcohols, aldehydes, isocyanates and isothiocyanates.

13. An improved lubricating oil of relatively low pour point comprising a petroleum fraction of relatively higher pour point having incorporated therein a small amount of a hydrogenated castor oil derivative having a softening point between about 70 F, and about 160 F., said hydrogenated castor oil derivative being the product of the reaction of hydrogenated castor oil with a neutral alcohol containing at least 6 carbon atoms.

14. An improved lubricating oil of relatively low pour point comprising a petroleum fraction of relatively higher pour point having incorporated therein a small amount of a hydrogenated castor oil derivative having a softening point between about 70 F. and about 160 F., said hydrogenated castor oil derivative being the product obtained by heating the hydrogenated castor oil at temperatures of about 330 F. to about 550 F.

15. An improved lubricating oil of relatively low pour point comprising a petroleum fraction of relatively higher pour point having incorporated therein a small amount of a hydrogenated castor oil derivative having a softening point between about 70 F. and about 160 F., said hydrogenated castor oil derivative being the product of the reaction of hydrogenated castor oil with a neutral isocyanate containing at least 6 carbo atoms.

16.. An improved lubricating oil of relatively low pour point comprising a petroleum fraction of relatively higher pour point having incorporated therein a small amount of a hydrogenated castor oil derivative having a softening point between about F. and about F., said hydrogenated castor oil derivative being the product of the reaction of hydrogenated castor oil with a neutral compound containing at least 6 carbon atoms selected from the class consisting of alcohols, aldehydes, isocyanates and isothiocyanates in the presence of a catalyst selected from the roup consisting of alkali metals, alkali metal alkoxides, alkaline earth oxides, lead oxide, tin x de, aluminum oxide, chromium oxide and nickel oxide.

17. A partially dewaYed parafiin base petroleum lubricating oil having incorporated therein a small amount of a hydrogenated castor oil derivative having a softening point between about 70 F. and about 160 F., said hydrogenated castor oil derivative being the product of the reaction of hydrogenated castor oil with a neutral compound containing at least 6 carbon atoms se lected from the class'consisting of alcohols, aldehydes, isocyanates and isothiocyanates.

18. A partially dewaxed parafiln base petroleum lubricating oil having incorporated therein a small amount of a hydrogenated castor oil derivative having a softening point between about 70 F. and about 160 F., said hydrogenated castor oil derivative being the product of the reaction of hydrogenated castor oil with a neutral alcohol containing at least 6 carbon atoms.

19. A partially dewaxed paraflln base petroleum lubricating oil having incorporated therein a small amount of a hydrogenated castor oil derivative having a softening point between about 70 F. and about 160 F., said hydrogenated castoroil derivative being the product of the reaction of hydrogenated castor oil with a neutral compound containing at least 6 carbon atoms selected from the class consisting of alcohols, aldehydes, isocyanates and isothiocyanates in the presence of a catalyst selected from the group consisting of alkali metals, alkali metal alkoxides, alkaline earth oxides, lead oxide, tin oxide, aluminum "oxide, chromium oxide and nickel oxide.

20. A lubricant comprising a petroleum lubricating oil having incorporated therein a small amount of a hydrogenated castor oil derivative having a softening point between about 70 F.

and about 160 F., said hydrogenated castor oil derivative being the product of the reaction of hydrogenated castor oil with a neutral aldehyde containing at least 6 carbon atoms.

21. A lubricant comprising a. petroleum lubricating oil having incorporated therein a small amount of a hydrogenated castor oil derivative having a softening point between about 70 F. and about 160 F., said hydrogenated castor oil derivative being the product of the reaction 01' hydrogenated castor oil with 2-ethyl hexenal.

22. An improved lubricating oil of relatively low pour point comprising a petroleum fraction of relatively higher pour point having incorporated therein a small amount of a hydrogenated castor oil derivative having a softening point between about 70 F. and about 160 F., said hydrogenated castor oil derivative being the product of the reaction of hydrogenated castor oil with a neutral aldehyde containing at least 6 carbon atoms.

23. An improved lubricating oil of relatively low pour point comprising a petroleum fraction of relatively higher pour point having incorporated therein a small amount of a hydrogenated castor oil derivative having a softening point between about 70 F. and about 160 F., said hydrogenated castor oil derivative being the product of the reaction of hydrogenated castor oil with 2-ethyl hexenal. l

24.- An improved lubricating oil of relatively low pour point comprising a petroleum fraction of relatively higher pour point having inooporated therein a small amount of a hydrogenated castor oil derivative having a softening point between about 70 F. andabout 160 F., said hydrogenated castor oil derivative being the product of the reaction of hydrogenated castor oil with dodecyl isocyanate.

MELVIN A. DIETRICH. 

